Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems (such as opaque touchpads integrated in, or peripheral to, notebook or desktop computers).
Gradient sensors are sensors that employ a voltage variation across one or more electrodes (usually a transmitter electrode) to assist in determining positional information. In many such sensors, the transmitter electrodes and/or sensor electrodes are communicatively coupled to associated circuitry via one or more conductive traces, electro-mechanical bonds, and the like, each having their own associated electrical resistance. The resistance introduced by conductive traces in series with the sensor electrodes are often unknown and can be significant. Accordingly, there is a need for systems and methods capable of determining the resistance of conductive traces in input devices.